of anderson



INITION APPARATUS Filed Dec. 31, 1931 Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE JOHN T. FITZSIMMONS, OF ANDERSON, INDIANA, ASBIGHOB TO DELOO BEIY CORPORA- TION, OF ANDERSON, INDIANA, A CORPORATION 01 DELAWARE IGNITION arrm'rus Application fled December 31, 1831. Serial Io. 584,10L

This invention relates to ignition apparatus for a two cycle internal combustion engine, and one of its objects is to operate the engine so that it will idle in a satisfactory manner. It has been found that a two cycle engine idles much better when only a part of the engine cylinders are fired durin the engine cycle. For example, a four cyhnder engine would normally fire four times during one revolution or one cycle of a two stroke cycle engine. Such engine would idle better when only two of the cylinders are fired during each engine cycle provided the firing intervals are not too irregular.

This aim of the present invention is accomplished by providing means responsive to the operation of the engine throttle for controlling the ignition apparatus in such a way that when the engine is idling part of the cylinders are provided with ignition sparks but when the engine is running all of its cylinders are provided with sparks.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a diagram illustrating a form of the invention.

Fig. 2 is a fragmentary view illustrating the device in another of its operating positions.

i alternates with the simultaneous firing of the cylinders #2 and #3. The ignition apparatus provides for firing cylinders 1 and 4 and then 2 and 3 simultaneously during the running of the engine; but; during idling,

3 the ignition apparatus provides for firing only one of each pair of cylinders. In other words, the firing is 1--342 such as might be the case of a four cycleengine. Hence the present invention may be said to be arranged to fire the engine as a four-cycle engine while idling and then automatically change to firing the engine as a two-cycle engine during running conditions.

In the disclosed embodiment of the present invention, a storage battery grounded at 11 is connected by a switch 12 with ignition coils and having primaries 21 and 41, respectively, and secondaries 22 and 42, respectively. The primaries 21 and 41 are connected by wires 23 and 43, respectively, with terminals 24 and 44. The terminals 24 and 44 are connected, respectively, by leaf s ring conductors 25 and 45, respectively wit circuit breaker levers 26 and 46 pivoted, respectively, at 27 and 47 and carrying rubbing blocks 28 and 48 which cooperate with a timer cam 29 carried by a shaft 30. The levers 26 and 46 carry contacts 31 and 51 cooperating, respectively, with grounded contacts 32 and 52. The leaf spring conductors 25 and serve to conduct current to the'contacts 31 and 51, respectively, from the terminals 24 and 44, respectively, and urge the rubbing blocks 28 and 48, respectively, toward the cam 29. The pair of timer contacts 31, 32 is shunted by a condenser 34 and the pair of contacts 51, 52 is shunted by a condenser 54.

The shaft 30 drives a distributor rotor indicated by 'dot-and-dash lines in the diagram. The rotor 60 carries a short segment 61 connected by brush 62 with a ring 63 connected by wire 64 with secondary 22. The rotor 60 carries a longer segment 65 bearing against a central terminal66 connected by wire 67 with secondary 42. The segments 61 and 65 move past distributor posts 68 carried by distributor head 69. The posts 68 are connected res ctively with various spark plugs 70 of t e engine. The posts 68 have. been numbered 1, 3, 4..and 2 in sequence to desi ate to which engine cylinder spark plugs t ey are connected.

During the idling of the engine the contact 31 is prevented from engaging the contact 32 by means comprising a non-conducting bar 71 attached to the lever 26 and held in the position shown'in Fig. 1 by a rod 72 urged toward the left by a spring 73. The rod 72 is provided with a portion of reduced diameter 74 which serves as a rivet for attaching to the rod 72, two oppositely disposed cup shaped washers 75 and 76 and a flexible diaphragm 77 located between them. The edge of diaphragm 77 is fastened between flanges 7 8 and 79 of suction chamber housing members80 and 81 respectively. The flange 7 9 is formed around the flange 78 as indicated by the flange 8'2 continuing from flange 79. The housing 80 provides a sleeve 83 for guiding the rod 72 and has a vent 80a. The housing 81 houses a tubular portion 84 and provides a seat for the spring 73 which is retained in position also by the washer 76. The tubular bushing 84 is connected by a pipe 85 with a carburetor passage 86 within which is located a throttle valve 87 mounted on shaft 88 and provided with notch 88a suflicient to provide for the passage of fuel while idling.

While the engine is idling there will be no suction or reduction of pressure in pipe 85, hence the spring 73 will be operative to maintain the circuit breaker lever 26 in the position shown in Fig. 1 against the pressure of the leaf spring conductor 25. Hence, the circuit breaker lever controlling the closing and separation of contacts 51 and 53 will be operative, only, and the ignition coil will be. operative, only, to produce sparking impulses. The distributor rotor and timer drive shaft 30 rotates at one-half engine speed and hence causes two sparking impulses to be generated by the coil 40 during each engine cycle or each revolution of the engine crank shaft. Therefore, there will be sparking impulses generated at the I end of each 90 of rotation of the rotor from the position shown. Assuming the rotation of shaft 30 to be clockwise, sparking impulses will be provided for cylinders #1 and #3 during one cycle of the operation of the engine and for cylinders #4 and #2 during the next cycle of operation. The engine will, therefore, idle with one-half the number of its cylinders firing. In other words, the engine will operate during two of its two-stroke cycles as it would operate during one cycle if it were a four-stroke cycle engine.

When the throttle-87 is open as shown at 87a to cause the engine to operate at part load, a suction is created at the entrance to pipe 85. Hence, the diaphragm 77 will be moved into the position 77a in Figs. 1 and 2 thereby causing the rod 72 to move from the position shown in Fig. 1 to that shown in Fig. 2, whereupon the circuit breaker including the contacts 31 and 32 will be permitted to operate in the usual way to control the generation of sparking impulses in the coil 20. Hence, during the running of the engine, both coils 20 and 40 will be simultaneously operated to generate sparking impulses simultaneously which will be conducted by segments and 61, so that cylinder 4 will be fired simultaneously with cylinder 1, and cylinder 2 will be fired simultaneously with cylinder 3. In this manner the engine is caused to operate as a two cycle engine during running conditions.

It is apparent therefore that the present invention provides means responsive tothe movement of the engine throttle for providing proper ignition for engine idling conditions by providing ignition for only a part of the engine cylinders, and for providing ignition for all the cylinders during engine running conditions.

While the form of embodiment of the present invention. as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Ignition apparatus for a multi-cylinder internal combustion engine comprising in combination, means for providing ignition impulses for all of the cylinders of the engines, and means responsive to engine operating conditions for controlling the ignition means so that only a part of the engine cylinders are provided with ignition impulses during idling.

2. Ignition apparatus for a multi-cylinder internal combustion engine comprising in combination, means for providing ignition impulses for all of the cylinders of the engine, and means responsive to engine throttle position for controlling the ignition means so that only a part of the engine cylinders are provided with ignition impulses during idling. I

3. gnition apparatus for a multi-cylinder internal combustion engine comprising in combination, means for providing ignition impulses for all of the cylinders of the engine, and engine suction operated means responsive to engine throttle position for controlling the ignition means so that only a part of the engine cylinders are provided with ignition impulses during idling.

4. Ignition apparatus for a. multi-cylinder internal combustion engine comprising in combination, means for providing ignition impulses for all of the cylinders of the engine and including two interrupters each controlling the ignition for a part of the engine cylinders, and means responsive to throttle movement for rendering one of said interrupters operative or non-operative.

5. Ignition apparatus for a multi-cylinder internal combustion engine comprising in combination means for providing ignition impulses for all of the cylinders of the engine, and including two interrupters each controlling the ignition for a part of the engine cylinders, and engine suction operated means responsive to throttle movement for render- 13 JOHN T. FITZSIMMONS. 

